Cyclopentadienyl-type ligands have found a number of uses in the past. As used herein, the term cyclopentadienyl-type ligands includes ligands containing a cyclopentadienyl-type group. Cyclopentadienyl-type groups as used herein contain a cyclopentadienyl functionality and include unsubstituted cyclopentadienyl, substituted cyclopentadienyl, unsubstituted indenyl, substituted indenyl, unsubstituted fluorenyl, and substituted fluorenyl groups. Such ligands have utility in the preparation of metallocenes useful for the polymerization of olefins.
Other applications for metallocenes include asymmetric hydrogenation, alkene epoxidation, alkene isomerization, ketone reduction, and as stoichiometric reagents for stereoselective cobalt-mediated reactions, allyltitanium addition reactions with aldehydes, and the highly selective formation of allylic amines.
It would therefore be desirable to produce a variety of novel ligands from readily available materials employing a simple and economical process.